Writing instrument



March 11, 1969v H. K. BROSS WRITING INSTRUMENT Filed Aug. 1, 196e INVENTOR Helmui: Kewl, voss 35.- ,glowwc La7/e,

Qttovmegs United States Patent O 3,432,244 WRITING INSTRUMENT Helmut Karl Bross, Weichselgartenstrasse 40, Altenberg, near Nuremberg, Germany Filed Aug. 1, 1966, Ser. No. 569,426 Claims priority, application Germany, Aug. 2, 1965,

3,10 U.S. Cl. 401-113 12 'Claims Int. Cl. B43k 7/12 ABSTRACT F THE DISCLOSURE The present invention relates to a Writing instrument which is provided with a mechanism which permits the writing element, for example, a ball-point insert or refill, to be moved axially Within the casing of the instrument from a retracted position to a forward or writing position or vice versa and to be arrested in either of these positions.

There are innumerable writing instruments of the above-mentioned type in use and on the market which are provided With mechanisms of many different designs. When the writing tip of the writing element of these instruments is in its retracted position, it is laterally covered by the casing, while it its forward position, it projects from the casing. The mechanism may be operated by exerting a pressure upon an actuating member, for example, a pushbutton or pressure cap, on the rear end of the instrument which is movable in the axial direction either in or on the casing. The forward movement of this actuating member occurs against the action of a compression spring and its retracting movement occurs by the action of this spring which is generally supported on a shoulder of the writing element.

It is an object of the present invention to improve such a writing instrument by providing it with a control mechanism which comprises two operating members which are movable relative to each other in the axial direction of the instrument and one of which consists of the actuating member which has an activating end and which is adapted to act upon the writing element, While the other'operating member is formed by the casing of the instrument, which casing surrounds the writing element and has, at the front end of the instrument a front opening through which the Writing element moves. One of these operating members is provided with at least one control cam which is movable in a radial direction relative to the longitudinal axis of the instrument and which is arranged to be pressed by a resilient force against the other operating member. When the actuating member is moved, this control cam will slide along guide edges which are provided on the other operating member, and it will thereby be moved selectively to end positions in which it will be arrested when the Writing element is in either the advanced or retracted positions.

The angular displacement of the sections of the different guide edges relative to each other constitutes an essential feature of the invention which is necessary for avoiding improper functions of the mechanism. In this connection it is important thatthe largest advance of 3,432,244 Patented Mar. 11, 1969 the actuating member from its retracted position is larger than the distance between the arresting positions. The forward arresting position will not be reached until under the action of the spring the actuating member or the cam has again been moved back for a short distance from its farthest possible advanced position- The guide edges according to the invention may be provided by step-shaped projections or recesses, which may be in the form of slot-shaped apertures, or by grooves, on one of the two operating members. Since that operating member which is provided with the guide edges is usually made of plastic by injection molding, it should be designed so as to be easily removed from the mold. This may be easily attained because of the particular arrangement of the guide edges in accordance With the invention. The high wear resistance of the mechanism according to the invention is due to the fact that, when the strongest load is exerted upon the actuating member, that is, when it is advanced from its retracted position, the control cam only needs to carry out a movement in a direction substantially parallel to the longitudinal axis of the instrument or its casing, while the movement of the control cam in the peripheral direction which is superimposed upon the longitudinal movement will not occur until the actuating member moves back from its farthest advanced position to the retracted position. The actuating member will then be relieved of the actuating pressure which is exerted thereon by the finger. The movement of the control cam in the peripheral direction may cause the actuating member to be likewise turned. If such a turning of the actuating member is undesirable, provisions have to be made to insure that the control cam will move in the peripheral direction independently of the actuating member. This may be attained, for example, by providing the control cam on an arm which is secured to the actuating member and adapted to be bent not only in the radial direction, but also in the peripheral direction.

If the actuating member is also to be turned, it is necessary that the control cam and the arm which might carry the same will oppose a peripherally directed force with such a resistance that the actuating member will be taken along in the peripheral direction by the movement of the control cam. In this case, the arm carrying the control cam should therefore be incapable of bending in the peripheral direction.

Even though when employing an actuating member in the form of a pushbutton, the guide edges are generally provided on the inner side of the casing of the writing instrument or, when employing a pressure cap, they are provided on the outer side of the casing, it is in principle also possible to provide the guide edges on the actuating member. The control cam and the arm on which the cam might be mounted would in such a case be provided on the casing of the Writing instrument.

When speaking of the casing of the writing instrument and of the actuating member in connection with the present invention,fthese terms are also meant to include any possible extensions or projections of these operating members on which the control elements according to the invention may be provided.

The improvements according to the invention consist primarily in designing the different parts of the mechanism, which are usually made of plastic and produced by injection molding, so as to be of a very simple shape, to permit them to be easily and quickly assembled, to operate properly at all times even though the extent of their relative movement is relatively small, and to be wear-resistant so that the writing instrument will be fully operative for a very long time.

The features and advantages of the present invention will become more clearly apparent from the following detailed description which is to be read with reference to the accompanying drawings, in which- FIGURE 1 shows, partly in section, a side view of a ball-point pen according to the invention, in which the actuating member is in its retracted position;

FIGURE 2 shows a view similar to FIGURE 1, in which the actuating member is in its depressed position;

FIGURE 3 shows a perspective view of the actuating member in the form of a pushbutton for a writing instrument according to the invention;

FIGURE 4 shows a side view of the most important part of a writing instrument according to a modification of the invention;

FIGURE 5 shows a cross section which is taken along the line V-V of FIGURE 4;

FIGURE 6 shows a longitudinal section of the rear part of a two-piece casing according to another modification of the invention;

FIGURE 7 shows a view of the rear casing part according to FIGURE y6, as seen in the direction of the arrow A; while FIGURE 8 shows an enlarged view of the part of the casing containing the guide edges.

In the drawings, in which all functionally similar parts are designated by the same reference numerals, the writing instrument according to the invention comprises a casing 1 in which an actuating member in the form of a push button 2 and a writing element 3, for example, in the form of a ball-point insert or refill, are slidable in the axial direction. When the upper end of the pushbutton 2 which projects from the open rear end of casing 1 is depressed, the lower end of this member will act upon the writing element 3 so as to shift the same from its retracted position within the casing against the action of a compression spring 4 to its writing position in which the writing tip 3 projects from the front end of casing 1. Spring 4 acts at one end upon a shoulder 1 on the inner wall of the casing and at its other end upon a flange 3" on the refill 3. As illustrated particularly in FIGURE 3, the part of the pushbutton 2 which is at all times located within the casing 1 is provided with an arm S which may be integral with the member 2. The free end of this arm is provided with a control cam 6 which projects toward the wall of casing 1 and has an inclined surface 6 extending at an angle downwardly and inwardly from its upper free end. On its upper side, cam 6 is provided with a work surface 6" which cooperates with the guide edges on the other operating member. As shown in FIGURE 3, this Work surface 6" is inwardly inclined from its outer edge. The guide edges 11, 9, and 7 are inclined in accordance with the inclination of work surface 6 of the cam. The inclination of these guide edges is designated in FIGURE 4 by the numerals 11', 9', and 7. This inclination of the guide edges and of the work surface of the cam insures a proper engagement of this work surface with the guide edges and thus a proper function of the mechanism.

According to the embodiments of the invention as illustrated in FIGURES 1 to 5, the guide edges for the control cam 6 are formed by slot-shaped apertures in the wall of casing 1, as may be seen particularly in FIG- URES 1, 2, and 4. The upper guide edge 11, the central or intermediate guide edge 7 and the lowest guide edge 9 are disposed above each other and are inclined relative to the vertical longitudinal axis of the writing instrument, and the upper guide edge 11 is inclined in the upward direction to the right and the two other guide edges 7 and 9 in the downward direction to the right. FIGURES 1, 2, and 4 also indicate the angular displacement of the guide edge sections, as previously described. In FIGURES l and 4, the control cam 6 is arrested in its rear end position in which the pushbutton 2 and the refill 3 are in their retracted position. This position of the control cam 6 is f determined by a stop corner 12 at the upper end of the guide edge 11. If a pressure is exerted upon the pushbutton 2 so as to push the latter forwardly, the inclined surface 6 of cam 6 runs against the edge of the slot directly opposite to the guide edge 11. This edge portion 12 upon which the cam then engages is preferably. designed so that the cam will not be acted upon by a force which tends to press the cam in the direction toward the remote end of the guide edge 11, and this edge portion 12' therefore preferably extends at a right angle to the longitudinal axis of casing 1. Cam 6 is thus pressed inwardly, whereby a spring force is produced in the radically resilient arm 5g which causes the cam `6 at a further forward movement of the pushbutton 2 to engage upon the part of the guide edge 7 which is located underneath the stop corner 12 within a line extending parallel to the axis of the casing. If the pushbutton 12 is then released, cam 6 will slide under the action of spring 4 along the guide edge 7 to the upper end thereof forming a stop corner 8. When cam 6 is in this position which is indicated in FIGURE 2, the pushbutton 2 and the refill 3 will be arrested in their forward position in which the writing tip 3' of the refill will project from the casing 1. When the pushbutton 2 is pushed forwardly from the position as shown in FIG- URES l and 4, it is, however, also possible that cam 6 while moving substantially parallel to the axis of the casing might be moved beyond the guide edge 7 to the farthest forward position. It is important that the cam will then not pass to the guide edge 9 so that when the pushbutton 2' is released and cam `6 moves back, it will not `be prevented from engaging with the guide edge 7 and from sliding to the stop corner 8. When the pushbutton is again depressed, cam 6 engages upon the edge 8 which also extends at a -right angle to the longitudinal axis of the casing and thereby moves out of the stop corner 8 and finally snaps in its farthest forward position behind the part of the lowest guide edge 9 which lies underneath the stop corner 8 and along which cam 6 will slide when ythe pushbutton 2' is released until it finally engages upon the guide edge 11 which permit the cam to slide back to the stop corner 12. Guide edge 10 which, as shown in FIGURES l and 2, is likewise formed by a slot-shaped aperture in the wall of the casing and connects the upper and lower guide edges with each other prevents the cam 6 from moving to the central guide edge 7. Such a movement which could occur because of a strong force acting upon the cam could possibly lead to an improper operation of the mechanism. In order to make this force as small as possible, the end surface 2' of the pushbutton is made of a spherical shape so that only a small friction will occur between the finger and the pushbutton 2 and the pushbutton may therefore be easily turned. The direction of the movement of the control cam t6 is once more indicated in FIGURE 8 by the arrows on the dot-and-dash line.

It is obvious that in place of the slot-shaped apertures forming the guide edges it is also possible to employ corresponding grooves in the wall of the casing. According to the modification as illustrated in FIGURES 4 and 5, the mechanism is designed so as to prevent the pushbutton from turning. Casing 1 as well as the pushbutton 2 are for this purpose made of a square cross section. Of course, by suitable conventional means it is also possible to prevent a rotation of the pushbutton 2 even if the casing has a circular cross section. In order to permit the control cam 6 to move in a peripheral direction even though the pushbutton is prevented from turning, arm 5 must be capable of bending in the peripheral direction. For preventing an improper function of the mechanism due to the resilient force which is produced by such bending of the arm, the inner side of the wall of casing 1 is provided with longitudinal ribs 13 and 14 which extend parallel to the axis of the casing and form guide edges 10 for guiding the cam 6 when moving during the actuation of pushbutton 2 from the stop corner 12 to the guide edge 7 or from the guide edge 9 to the guide edge 11 along aline which extends substantially parallel to the axis of the casing. Arm of the embodiment according to the invention as illustrated in FIGURE 4 will be in its so-called neutral position, i.e. in the position in which no spring force will act upon the arm in the peripheral direction, when cam 6 is located in the stop corner 8. Arm 5 may, however, also be mounted on pushbutton Z so that the neutral position Will occur in any other position of cam 6, for example, in the stop comer .12. The guide edges which extend substantially parallel to the axis of the casing between the guide edges 11, 7, and 9 should in any event be designed so as to prevent the arm 5 from bending to an undesirable extent in lateral directions. The edge -portions 12 and 8 are designed to as to have a small incline in the direction opposite to that of the guide edges 11 and 7.

While in the embodiments of the invention as previously described the guide edges 11, 7, and 9 lare formed by slot-shaped apertures in the wall of casing 1, they are formed in the embodiment according to FIGURES 6 and 7 by offsetting certain surface parts 16, 15, 18, and 17 of the inner side of the casin'g in steps relative to each other. Thus, the surface is farther toward the outside from the longitudinal axis of casing 1 than the surface 16, surface 18 is farther toward the outside than surface 15, and surface 17 is farther to'ward the outside than surface 18. By the step between surface 17 and surface 18 a guide edrge is fonmed which extends parallel to the axis of the easing and along which cam 6 will slide when it moves from the inclined lguide edge 9' to the guide edge 11. Between the surface 17 and the surface 15 a beveled part 20 is provided upon which cam 6 will slide so as to be lifted to the level of surface 15. This modification of the mechanism maybe employed especially if the easing consists of two parts. The pushbutton may then be inserted into the rear part of the casing from the opening in the front side thereof.

In order to facilitate the assembly of the mechanism according to the invention, several groups of the abovementioned guide edges may be provided on the inner wall of the casing.

Although my invention hlas been illustrated and described with reference to the preferred embodiments thereof, I wish to have it understood that it is in no way limited to the details of such embodiments but is capable of numerous modifications within the scope of the appended claims.

Having thus fully disclosed my invention, what I claim is:

1. In a writing instnument having a front end and a rear end *and provided with at least one writing element slidable in the direction of the axis of said instrument, and a control mechanism for selectively moving said writing element forwardly into a forward position for writing and for retracting it into a retracted position and for arresting said writing element in its fonward position or in its retracted position, said mechanism comprising two operating members movable relative to each other in the axial direction of said instrument, one of said operating members constituting a casing for said instrument surrounding said writing element and having at said front end of said instrument a front opening throuigh which said writing element moves, and the other of said operating members including an actuating member at said rear end of said instrument, said actuating member having an actuating end, being operatively associated with said Writing element, and being arranged to be depressed so as to act upon said writing element, and a spring associated with said Writing element for acting against the fonward movement of said actuating member and said writing element and tending to move them to the retracted position, one of said operating members being provided with at least one control cam which is movable in a radial direction relative to the longitudinal axis of said instrument and arranged to be pressed, under the action of a substantially resilient force, against the other said operating member, said other operating member including means defining guide edges along whicl said cam is arranged to move when said actuating member is being moved and then moving to, and being tarrester in, stop positions when said writing element is movecl selectively to its forward or retracted positions, the irnprovement wherein: at least one group of three guide edges -is provided which are disposed one above the other along the longitudinal axis of said instrument tc present an uppermost guide edge, an intermediate guide edige, and a lowest guide edge, said uppermost guide edge being furthest from said front opening and all ol said guide edges being inclined relative to the vertical longitudinal axis of said rwriting instrument, each oi said guide edges having a near end and a remote end, as seen with reference to said actuating end of said actuating member; the lowermost two of said guide edlges are inclined in the same direction; at said near end of said uppermost `guide edge a stop corner is provided for arresting said control cam in said retracted position of the writing element and at said near end of said intermediate guide edge a stop comer is provided for arresting said control cam in said forward position of said writing element; said intermediate guide edge is provided with a section which is located along a line extending parallel to said longitudinal axis and underneath one end of said uppermost guide edlge; said lowest guide edge is provided with a section which is located along a line extending parallel to said longitudinal axis and underneath said stop corner of said intermediate guide edge; said remote end of said lowest guide edge is angularly displaced relative to said remote end of said intermediate guide edge in the direction of its incline; said lowest lguide edge is continued by a section which is angularly displaced relative to said stop corner of said intermediate lguide edge and which lies along a line extending parallel to said longitudinal axis and underneath a section of said upper-most guide edge which is |also angularly displaced relative to said intermediate guide edge stop corner; said angular displacements are so dimensioned that, when said actuating member is moved forwardly from its retracted position, the path of cam movement extending beyond said intermediate guide edge lies outside of the effective ran-ge of said lowest guide edge and the path of cam movement from said lowest to said uppermost guide edge lies outside of the effective range of said -intenmediate lgfuide edge; and said cam is provided rwith a work surface 'which is operatively associated with said guide edges.

2. A writing instrument as defined in claim 1 Iwherein the inclination of said uppermost guide edge extends in the opposite direction to the inclination of the other two of said guide edges.

3. A writing instrument as defined in claim 1 wherein said guide edges 'are provided on grooves, and said cam has an inclined part which, during the forward movement of said actuating member, cooperates with those edges of said grooves which are opposite to each of said guide edges,

4. A 'writing instrument as defined in claim 3, the edges of said grooves opposite to said stop corners of the lguide edges extend at right angles to the longitudinal axis of said casing.

45. A writing instrument las defined in claim 3 wherein the edges of said grooves opposite to said stop comers of the 'guide edges are inclined in the opposite direction to the incline of said guide edges.

6. A writing instrument as defined in claim 1, said other operating member is tubular and has an inner wall provided with Ia plurality of intermediate surface parts between which said guide edlges are formed so as to be sp'aced at different distances from the axis of said casing.

7. A writing instrument as dened in claim 6 wherein the distance of said surface parts from the axis of said casing increases in the direction of movement of said cam from said uppermost I.guide edge to s'aid lowest guide edge,

and within the path of movement of said cam from said lowest to said uppermost guide edge an inclined surface is provided and positioned for permitting said cam to slide from that surface iwhich is most remote from said actuating end of said actuating member to that surface Iwhich is nearest to said actuating end.

8. A writing instrument as deined in claim 1 wherein said actuating member is arranged to be turned and further comprising a further guide edge provided along the path of movement of said cam from said lowest to said uppermost guide edge, said further guide edge extending substantially parallel to the axis of said instrument for preventing said actuating member from turning along said path.

9. A writing instrument as defined in claim 1 further comprising an arm integral with said actuating member and wherein said actuating member is prevented from turning, said cam is mounted on said arm, said arm is arranged to be bent both in radial and peripheral directions for producing a resilient force.

10. A writing instrument as defined in claim 9, further comprising additional guide edges with which said cam cooperates tand extending parallel to the axis of said instrument for preventing an undesirable pivoting of said arm under the action of such resilient force.

11. A writing instrument as defined in claim 3- additionally comprising a further guide edge extending parallel to the axis of said instrument along the path of movement of said cam from said lotwest to` said uppermost guide edge, said further guide edge being provided on a groove fwhich connects said grooves on ywhich said uppermost and lower guide edges are provided.

12. A writing instrument as defined in claim 1 wherein said work surface of said cam is inwardly inclined from its outer side, and each of said :guide edges has an inclination behind which said work surface engages.

References Cited UNITED STATES PATENTS 3,196,839 7/1965 Bertoglio et al 401-112 FOREIGN PATENTS 894,355 4/ 1962 Great Britain.

LAWRENCE CHARLES, Primary Examiner. 

